In the food, beverage, and agricultural industry, preservatives are commonly added to various types of foods and drinks to maintain freshness. Of those preservatives, sulfur dioxide is often used to preserve dried fruits by preventing spoilage and maintaining a healthy appearance of the fruit. For large-scale production and distribution, sulfur dioxide plays a crucial role in protecting the vibrant color of golden raisins, while also extending their shelf life.
While sulphur dioxide is a viable preservative for dried fruits, as well as many other types of foods, its potential impact on human health has brought about cautiousness concerning the amounts of the preservative found in our foods. In some cases, limitations on the maximum allowable concentrations of sulphur dioxide (and sulfites, in general) in various types of foods and drinks are set in place by governmental authorities. As a result of such regulations, as well as general public awareness, food and beverage producers are seeking out better methods for reducing the amounts of preservatives found in their products.
For the fruit industry, it is equally important to produce viable dried fruits with a minimal amount of preservatives. With respect to conventionally processed golden raisins, sulphur dioxide concentrations tend to range from about 2000 ppm to 3500 ppm, which, in relation to other sulfite-containing foods, is relatively high—possibly increasing the chances of health complications, especially for those who may be sensitive to sulfites. It is therefore desirable for improved production methods which can reduce sulfite concentrations in golden raisins, as well as in other types of fruits, without degrading the physical or nutritional quality thereof.